In your wildest dreams you couldn’t make up a story about a sinkhole swallowing eight ultra-valuable supercars at the National Corvette Museum in Kentucky. But that’s exactly what happened early Wednesday morning—surveillance video captured the floor opening up and the cars falling…a long way down. The hole is 40 feet wide and 20 feet deep. A lot of people have heard about it by now, but did you wonder why a sinkhole would suddenly open up in the earth?

Apparently, the museum (just down the street from the Corvette factory) is also very close to the Mammoth Cave National Park, and there was a previously unknown cavern below the museum. This stuff happens all over the world. I visited a sinkhole near the Dead Sea in Israel that had taken out a road.

Says the Seattle Times, “These underground craters can open up in an instant, sucking in whatever lies above and leaving the surrounding area looking like an earthquake zone.” There are now 3,000 sinkholes in Israel, and the issue is a water shortage. As the Dead Sea dries up (it’s down a third since the 1960s), underground fresh water takes the place of salt water and eats away at the salt layer, causing the collapses.

Sinkholes form when a cave occurs in the limestone with a natural conduit or pipe going up toward the surface. If the soil above the conduit is repeatedly wetted by rain, or by human development activities, such as gutter downspouts, the covering soil erodes from below, forming an underground soil arch. It eventually collapses when the layer of soil gets too thin to support its own weight or something punches through it—like a truck.

Or, of course, a Corvette. The cars that went into the hole, according to CNN, are:

1962 “Black Corvette”

1984 PPG pace car

2009 ZR1 “Blue Devil”

1992 white “1 Millionth Corvette”

1993 ruby red “40th Anniversary Corvette”

2001 Mallett Hammer Z06 Corvette

2009 white “1.5 Millionth Corvette”

1993 ZR-1 Spyder

The Sky Dome wing that collapsed is going to stay closed for a while--there is millions of dollars worth of damage--but the rest of the museum is still open for business. Here's some drone footage of the 'Vettes in the hole: